A variety of studies have been conducted on enhancement of thermal efficiency of combustors. If thermal efficiency at combustion is increased by 5%, it will become possible to cut back on fuel as a natural resource and fuel costs by 5% every month, leading to significant industrial advantages.
Therefore, there have been improved burners such as the invention described in JP 11-1707 A, for example.
On the other hand, some heaters among combustors were provided with a far infrared radiator for enhancement of heating efficiency. For example, as described in JP 2003-336811 A, an external glass cylinder is provided around a red heat section, a far infrared radiation is emitted from the heated external glass cylinder, and good heating can be thus obtained.
However, the far infrared radiation used here is associated with the heating of a far infrared radiator emitting an infrared radiation, and has been used exclusively for warming the body.
Patent Document 1: JP 11-1707 A
Patent Document 2: JP 2003-336811 A